[en] The stochastic stability in the large of stationary equilibria of ideal and dissipative magnetohydrodynamics under the influence of stationary random fluctuations is studied using the direct Liapunov method. Sufficient and necessary conditions for stability of the linearized Euler-Lagrangian systems are given. The destabilizing effect of stochastic fluctuations is demonstrated. (orig.)

[en] The stochastic stability of stationary magneto-hydrodynamic or plasma equilibria under the influence of stationary random fluctuations is studied using the direct Liapunov method. The destabilizing effect of fluctuations is demonstrated. (orig.)

[en] The global stability of stationary equilibria of dissipative MHD is studied uisng the direct Liapunov method. Sufficient and necessary conditions for stability of the linearized Euler-Lagrangian system with the full dissipative operators are given. The case of the two-fluid isentropic flow is discussed. (orig.)

[en] Analytical study of the linear stability of one-dimensional double layers in nonmagnetized plasmas based on the solution of the Vlasov-Poisson system is presented. Electromagnetic effects are not included. A self-consistent equilibrium electrostatic potential PHI₀(z) that monotonically increases from a low level z = -infinity to a high level at z = + infinity is assumed. This potential is modelled as a piecewise continuous function of z and we assume that PHI₀(z) has constant values for -infinity < z <= O and L <= z < infinity, L being the thickness of the double layer. The BGK states for the Vlasov-Poisson system provide an explicit expression for the velocity distribution of the reflected electrons required for the particular double layer configuration. The stability of the double layers is studied via the linearized Vlasov and Poisson equations using the WKB approximation. (author)

[en] The stability of non-relativistic runaway electron distributions with respect to the anomalous Doppler resonance is examined in a range of parameters of interest to tokamaks, i.e., for Y identical to ω/sub pe//Ω/sub ce/ ≤ 2 and for ohmic electric fields ε identical to E/E/sub c/ ≤ 0.1. Distribution functions are calculated numerically within a region up to 35 v/sub e/ (thermal velocities) using a finite-element 2-D Fokker-Planck code. Alternatively, an analytic approximation for the runaway distribution function is used, valid beyond the critical velocity v/sub c/ ≅ v/sub e/ (E/sub c//E)/sup 1/2/. Stability thresholds in (ω, k/sub parallel/) - space are then determined

No abstract available

[en] The stability of a steady finite-amplitude whistler wave penetrating a collisionless, unbounded, homogeneous plasma is studied. The supporting wave as well as the excited side-band waves are assumed to propagate parallel to an uniform magnetostatic field B_o. For a general form of the distribution function of trapped electrons, the growth (damping) rates of side-band modes are calculated. It is shown that a particular distribution of trapped electrons gives rise to strongly unstable side-band electromagnetic modes having right-hand polarization. The spectrum of unstable electrostatic and electromagnetic satellite waves is analyzed

No abstract available

[en] The stochastic stability of stationary magnetohydrodynamic or plasma equilibria under the influence of stationary random fluctuations is studied using the direct Liapunov method. The destabilizing effect of fluctuations is demonstrated. (Auth.)

No abstract available